In an Long Term Evolution (LTE) system, uplink data of user equipment (UE) is scheduled by using Physical Downlink Control Channel (PDCCH) signaling of a base station. The base station is clear about whether the UE needs to transmit data at any moment. Regardless of whether the base station misses detecting or incorrectly detects data transmitted by the UE, the base station feeds back a negative acknowledgement message to the UE on an acknowledgement resource corresponding to the UE. However, in a contention-based transmission manner, uplink data transmission by the UE is an indefinite event for the base station. When the base station misses detecting uplink data transmitted by the UE, the base station considers that the UE has not transmitted the data, and therefore, the base station does not feed back an acknowledgement message on the acknowledgement resource corresponding to the UE. Consequently, erroneous determining of an uplink data transmission situation is caused.